By early childhood, children who will later develop a primary psychotic disorder are already demonstrating many of the deficits that are closely associated with the disease in the adult. For example, even though diagnostic symptomotology may be a decade or more away, psychosis-associated deficits in physiology (e.g. impairments in smooth pursuit eye tracking) and cognition (e.g. attentional deficits) are fully identifiable by 6- years of age. That psychosis-associated deficits are fully present in children this young lends support to the neurodevelopmental hypothesis of primary psychotic disorders. This hypothesis suggests that "events" (i.e. genetic, environmental, or both) early in development sets the stage for an abnormal developmental trajectory for the individual. While the exact "event(s)" has not been identified, and may indeed vary across individuals, the central tenet of this hypothesis is that it occurs early on in development, perhaps prenatally. This research project addresses a very important issue in neurodevelopmental research-abnormal neurodevelopment leads to abnormalities in behavior, physiology and attention. By using a task which has consistently been interpreted as demonstrative of abnormal brain functioning in adults and children with a primary psychotic disorder, as well as many of their close, unaffected relatives, we can contribute to the understanding of the developmental trajectory of this devastating disorder. Infants will be tested at 26 weeks of age (6 months) using a smooth pursuit eye movement paradigm. While infants "track" moving stimuli across a video monitor, eye movements will be recorded using infrared eye-tracking technology. Additionally, heart rate, which will be analyzed as a measure of attention, will be monitored. It is hypothesized that infants with a family history of a primary psychotic disorder will demonstrate abnormal patterns of eye tracking when compared to infants with no family history. PUBLIC HEALTH RELEVANCE: By early childhood, children who will later develop schizophrenia are already demonstrating many of the deficits that are closely associated with the disease in the adult. This project will answer questions that are at the core of the neurodevelopmental hypothesis of schizophrenia. Understanding early developmental abnormalities has the potential to aid in diagnosis, treatment or when combined with other information, new prevention strategies. By studying infants at 26 weeks of age, we will be able to evaluate the development of smooth pursuit eye movements, attention as indexed by heart rate changes and the interaction of these measures.